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PETRONAS TECHNICAL STANDARDS

DESIGN AND ENGINEERING PRACTICE

TECHNICAL SPECIFICATION

TURBINE FISCAL METERINGSYSTEMS FOR LIQUIDHYDROCARBONS

PTS 32.32.00.11SEPTEMBER 2002

2010 PETROLIAM NASIONAL BERHAD (PETRONAS)All rights reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means (electronic,

mechanical, photocopying, recording or otherwise) without the permission of the copyright owner

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PREFACE

PETRONAS Technical Standards (PTS) publications reflect the views, at the time of publication,of PETRONAS OPUs/Divisions.

They are based on the experience acquired during the involvement with the design, construction,operation and maintenance of processing units and facilities. Where appropriate they are basedon, or reference is made to, national and international standards and codes of practice.

The objective is to set the recommended standard for good technical practice to be applied byPETRONAS' OPUs in oil and gas production facilities, refineries, gas processing plants, chemicalplants, marketing facilities or any other such facility, and thereby to achieve maximum technicaland economic benefit from standardisation.

The information set forth in these publications is provided to users for their consideration anddecision to implement. This is of particular importance where PTS may not cover everyrequirement or diversity of condition at each locality. The system of PTS is expected to besufficiently flexible to allow individual operating units to adapt the information set forth in PTS totheir own environment and requirements.

When Contractors or Manufacturers/Suppliers use PTS they shall be solely responsible for thequality of work and the attainment of the required design and engineering standards. Inparticular, for those requirements not specifically covered, the Principal will expect them to followthose design and engineering practices which will achieve the same level of integrity as reflectedin the PTS. If in doubt, the Contractor or Manufacturer/Supplier shall, without detracting from hisown responsibility, consult the Principal or its technical advisor.

The right to use PTS rests with three categories of users :

1) PETRONAS and its affiliates.2) Other parties who are authorised to use PTS subject to appropriate contractual

arrangements.

3) Contractors/subcontractors and Manufacturers/Suppliers under a contract withusers referred to under 1) and 2) which requires that tenders for projects,materials supplied or - generally - work performed on behalf of the said userscomply with the relevant standards.

Subject to any particular terms and conditions as may be set forth in specific agreements withusers, PETRONAS disclaims any liability of whatsoever nature for any damage (including injuryor death) suffered by any company or person whomsoever as a result of or in connection with theuse, application or implementation of any PTS, combination of PTS or any part thereof. Thebenefit of this disclaimer shall inure in all respects to PETRONAS and/or any company affiliatedto PETRONAS that may issue PTS or require the use of PTS.

Without prejudice to any specific terms in respect of confidentiality under relevant contractual

arrangements, PTS shall not, without the prior written consent of PETRONAS, be disclosed byusers to any company or person whomsoever and the PTS shall be used exclusively for thepurpose they have been provided to the user. They shall be returned after use, including anycopies which shall only be made by users with the express prior written consent of PETRONAS.The copyright of PTS vests in PETRONAS. Users shall arrange for PTS to be held in safecustody and PETRONAS may at any time require information satisfactory to PETRONAS in orderto ascertain how users implement this requirement.

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PTS 32.32.00.11September 2002

Page 3

TABLE OF CONTENTS

1. INTRODUCTION.................................................................................................... 51.1 SCOPE.................................................................................................................. 51.2 DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS......... 5

1.3

DEFINITIONS ........................................................................................................ 51.4 ABBREVIATIONS .................................................................................................. 5

1.5 CROSS-REFERENCES......................................................................................... 61.6 ORDER OF PRECEDENCE................................................................................... 61.7 CHANGES FROM PREVIOUS EDITION................................................................ 6

2. MANUFACTURER'S RESPONSIBILITY................................................................ 7

3. METERING SYSTEM DESIGN .............................................................................. 83.1 GENERAL.............................................................................................................. 83.2 SYSTEM AVAILABILITY ........................................................................................ 83.3 RANGEABILITY..................................................................................................... 93.4 VALIDATION.......................................................................................................... 93.5 INLET HEADER................................................................................................... 11

3.6

METERING RUN ................................................................................................. 113.7 METER PROVER................................................................................................. 11

3.8 MICROCOMPUTER-BASED MONITORING AND CONTROL SYSTEM............... 113.9 UTILITIES............................................................................................................ 12

4. TECHNICAL REQUIREMENTS FIELD-MOUNTED COMPONENTS................. 144.1 SKID, STRUCTURAL AND BASEPLATE ............................................................. 144.2 MATERIALS......................................................................................................... 154.3 INSTRUMENTATION AND ELECTRICAL ............................................................ 164.4 TURBINE METERS.............................................................................................. 184.5 STRAINERS ........................................................................................................ 194.6 FLOW STRAIGHTENERS.................................................................................... 204.7 FLOW CONTROL VALVES.................................................................................. 21

4.8

TEMPERATURE MEASUREMENT...................................................................... 224.9 PRESSURE MEASUREMENT ............................................................................. 23

4.10 DENSITY MEASUREMENT ................................................................................. 244.11 WATERCUT MEASUREMENT............................................................................. 254.12 SAMPLER............................................................................................................ 264.13 METER PROVER................................................................................................. 274.14 PAINTING............................................................................................................ 28

5. TECHNICAL REQUIREMENTS - MONITORING AND CONTROL SYSTEM........ 295.1 STREAM MICROCOMPUTER ............................................................................. 295.2 STATION MICROCOMPUTER............................................................................. 295.3 PROVER MICROCOMPUTER............................................................................. 305.4 DATA INTEGRITY AND SECURITY..................................................................... 32

6.

FACTORY AND FIELD INSPECTION AND TESTING ......................................... 336.1 GENERAL............................................................................................................ 33

6.2 INSPECTION FOR COMPLIANCE WITH METERING DESIGN ........................... 336.3 INSPECTION AND TESTING OF PIPING SYSTEMS........................................... 336.4 INSPECTION FOR ELECTRICAL SAFETY.......................................................... 346.5 CALIBRATION FACILITIES.................................................................................. 346.6 MASS AND VOLUME FLOW COMPUTATION SYSTEM...................................... 346.7 FUNCTIONAL TESTING OF THE COMPLETE METERING SYSTEM.................. 366.8 WATERCUT MEASUREMENT, DENSITY MEASUREMENT AND SAMPLERS.... 366.9 SITE ACCEPTANCE TEST.................................................................................. 36

7. PRESERVATION AND PREPARATION FOR SHIPMENT ................................... 377.1 PRESERVATION................................................................................................. 377.2 PREPARATION FOR SHIPMENT ........................................................................ 37

8. DOCUMENTATION ............................................................................................. 38

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8.1 REQUIREMENTS ................................................................................................ 388.2 MANUALS............................................................................................................ 388.3 CERTIFICATES ................................................................................................... 38

9. REFERENCES..................................................................................................... 39

APPENDICES

APPENDIX 1 TYPICAL LIQUID HYDROCARBON FISCAL MEASUREMENT FLOWSCHEME..................................................................................................... 42

APPENDIX 2 FIELD SIGNAL CONNECTIONS AND TRANSFER ..................................... 43

APPENDIX 3 DISPLAY, TRANSFER AND UTILISATION OF DATA ANDCALCULATED VALUES.............................................................................. 44

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1. INTRODUCTION

1.1 SCOPE

This PTS defines the minimum requirements for turbine metering systems (including in-situ

proving equipment) for the measurement of the quantity and the quality of liquidhydrocarbons passing through an accounting facility such as at the inlet or outlet of an oilpipeline or at a ship loading station.

This PTS is a revision of the PTS of the same title and number dated November 1993. Asummary of changes from the previous edition is listed in (1.7).

The Principal may consider alternate measurement systems, e.g., Pd meters, Coriolis,vortex, etc., but these are not covered by this PTS.

This PTS shall be used in conjunction with Requisition Sheet PTS 32.32.00.93

1.2 DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS

Unless otherwise authorised by PETRONAS, the distribution of this PTS is confined to

companies forming part of or managed by PETRONAS, and to Contractors andManufacturers/Suppliers nominated by them.

This PTS is primarily intended for use in oil and gas production facilities, but may also beused in oil refineries, chemical plants, gas plants and supply/marketing installations.

If national and/or local regulations exist in which some of the requirements may be morestringent than in this PTS, the Contractor shall determine by careful scrutiny which of therequirements are the more stringent and which combination of requirements will beacceptable with respect to health, safety, environmental, economic and legal aspects. In allcases the Contractor shall inform the Principal of any deviation from the requirements ofthis PTS which is considered to be necessary in order to comply with national and/or localregulations. The Principal may then negotiate with the Authorities concerned with the objectof obtaining agreement to follow this PTS as closely as possible.

1.3 DEFINITIONS

The Contractor is the party that carries out all or part of the design, engineering,procurement, construction, commissioning or management of a project or operation of afacility. The Principal may undertake all or part of the duties of the Contractor.

The Manufacturer/Supplier is the party that manufactures or supplies equipment andservices to perform the duties specified by the Contractor.

The Principal is the party that initiates the project and ultimately pays for its design andconstruction. The Principal will generally specify the technical requirements. The Principalmay also include an agent or consultant authorised to act for, and on behalf of, the

Principal.The word shallindicates a requirement.

The word shouldindicates a recommendation.

1.4 ABBREVIATIONS

CCR - Central Control RoomDCS - Distributed Control SystemIP - Institute of PetroleumLCR - Local Control RoomMESC - Materials, Equipment, Standards and CodeNEMA - National Electrical Manufacturers Association

RTD - Resistance Temperature Detection ElementSCADA - Supervisory Control and Data Acquisition System

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1.5 CROSS-REFERENCES

Where cross-references to other parts of this PTS are made, the referenced sectionnumber is shown in brackets. Other documents referenced in this PTS are listed in (9).

1.6 ORDER OF PRECEDENCE

In case of conflict between documents relating to the enquiry/order, the following priority ofdocuments shall apply:

1. National or legal codes or regulations2. The Purchase Order3. The Requisition, see PTS 32.32.00.934. This PTS5. Other PETRONAS, industry, national and international standards referenced herein.

Any conflict of requirements that cannot be resolved by the above order of precedenceshall be referred to the Principal for resolution.

1.7 CHANGES FROM PREVIOUS EDITION

The previous edition of this PTS was dated November 1993. Other than editorial changes,the following are the major changes to the previous edition.

Section Subject

1.1 Added reference to Requisition Sheet, PTS 32.32.00.93

2 Recommendation to use commercially available flow computers.

3.1 Use of uncertainty instead of accuracy in line with ISO TR 5168.

3.2 Added new section on system availability.

3.3 Added new section on rangeability.

3.4 Added new section on validation.

3.8 Added recommended use of digital transmission from field transmittersto flow computers.

3.9 Added further details on vital power supply requirements.

4.3 Added additional details on hazardous area classification andcertification.

Added reference to IEC 60654 and 60721 on environmental conditions.

4.9 and 6.5 Added optional requirement for supply of field calibration standard for

verification / calibration of equipment.

9 Updated references to standards.

Appendix 2 Added optional Hart or other digital communication.

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2. MANUFACTURER'S RESPONSIBILITY

The Manufacturer's scope of work shall include design, fabrication, inspection, testing,delivery, supply of documentation and the initial calibration of the complete liquid meteringsystems.

The Manufacturer shall assume full system responsibility. This means that theManufacturer shall ensure the operability, accuracy and quality of all components includingthose of the Manufacturer's sub-suppliers and, in addition, conformance to authority andcode requirements.

Equipment offered by the Manufacturer shall be in accordance with the Principal'sPreferred Vendor List for Instrumentation and Computers. Equipment shall be proven andshall comply with the relevant codes.

The Manufacturer's design shall recognise that simplicity, and consequently minimisation offield installation work, is of prime importance. The design shall also provide ease of accessto all components, maximise maintainability (including calibration) and include facilities tocontain (and properly dispose of) liquid spills resulting from operational assembling and

raining activities.The Manufacturer shall prepare a detailed specification for the microprocessorinstrumentation and for programming software. The Manufacturer shall apply commerciallyavailable, state-ofthe-art flow computers, approved by local fiscal authorities. Deviationfrom this is subject to approval in writing by the Principal. Where applicable, theManufacturer shall be required to liaise with the main data acquisition system Supplier (tobe advised by the Principal) to arrange the data links and protocols necessary formonitoring of the metering system.

The Manufacturer shall immediately inform the Principal if there is doubt on the specifiedrequirements. The Manufacturer shall not proceed with any aspect of the work until he hasreceived the necessary written confirmation from the Principal.

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3. METERING SYSTEM DESIGN

3.1 GENERAL

The metering system shall be considered as two major sub-systems. These are:

i) the field-mounted skid including the sampling and proving equipment, andii) the computing facility in the CCR, LCR or local equipment room for calculation, display

and control.

The metering system shall indicate measurement uncertainty for accounting purposes asrequired by this PTS for mass and volumetric quantities and the flow rates of the liquidhydrocarbon together with its temperature, pressure, density, and water content prior todelivery into downstream systems. It shall incorporate sufficient parallel meter runs toenable the maximum and minimum flow rates to be measured at the specified uncertainty,and to within the specified availability and to cater for validation exercises when one of themeter runs is taken offline. Fiscal metering installations are usually subject to approval bylocal authorities. This normally covers approval of the design through to final installation.Those authorities should be consulted at the earliest possible stage and thereafter, in order

to gain acceptance of the metering philosophy and to simplify final approval of theinstallation.

Although sales contracts frequently specify accuracy to define the performance of thesystem, this PTS uses uncertainty in line with ISO TR 5168. The final metering systemuncertainty shall be better than the figure specified in the sales agreement(s).

The skid package shall be suitable for the location's prevailing environmental conditions asspecified in the Requisition. The skid shall include all pipework manifolds, meteringstreams, valves, instruments and fittings. It shall be supplied as a fully piped, cabled, andinstrumented package.

Operational experience has shown that the maximum differential pressure across thecomplete metering system should be less than 200 kPa.

A typical flow scheme for a fiscal metering station is contained in(Appendix 1)of this PTS.

3.2 SYSTEM AVAILABILITY

The metering system shall be arranged in such a way that a single failure with its relatedfailures does not result in a complete loss of measurement. This means:

The power supply of the measuring station up to and including the fieldinstrumentation shall be redundant. However, failure of the power supply incombination with a failure of the back-up supply need not be assumed in thedesign.

The pressure measurement and temperature measurement shall be redundant.

At least the flowmeter with the highest range shall be redundant.

The flowcomputer shall have back-up facilities. The turbine meter electronics shallhave non-resettable mechanical counters.

A spare instrument or an alternative method shall be available to determinephysical properties of the liquid.

The metering system availability shall be as specified in the Requisition. This can beachieved by the following combined set of measures:

Selection of components with a high inherent availability.

Installation of a number of parallel streams (for instance 2 x 100 % or 3 x 50 %,which may also be required for turndown reasons)

Availability at site of the required spares and the appropriate resources to replacethe faulty components.

The Manufacturer shall include an availability calculation with his proposal.

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3.3 RANGEABILITY

The design capacity of the metering system is the maximum flowrate that can bemeasured. This is the sum of all but the spare runs to 100 % of max. output.

The minimum capacity is the flowrate of the smallest single run with an uncertainty (2 )

equal to the design specification of the turbine meter.

The rangeability is defined as the ratio of these flowrates and shall be as specified in theRequisition.

Provisions shall be made to stop the flow at rates below a preset minimum value.

3.4 VALIDATION

3.4.1 General

As part of the tender, the Manufacturer shall propose auditable procedures and instructionspertaining to the validation and maintenance of the metering station. These proceduresshall ensure that the measuring station is validated and maintained so as to retain itsdesign performance during its service life.

Validation comprises calibration and, if necessary, adjustment of the turbine meters and thesecondary instrumentation pertaining to the metering station. A component shall only beadjusted if its calibration shows errors outside the maximum permissible error limits.

3.4.2 Traceability

Calibration procedures and instructions shall be traceable to national standards.

3.4.3 Calibration equipment

Equipment used for calibration, if included in the scope of supply, shall have a validcalibration certificate issued by a national or accredited laboratory. Such equipment shall

have an uncertainty of measurement of maximally one third of the uncertainty of theinstruments to be calibrated under the conditions at which the tests take place. Calibrationcertificates shall specify the systematic error in the measurement result as a function ofcalibrated range and include a statement on the uncertainty of the calibration results.

3.4.4 Calibration intervals

Initial minimal calibration intervals shall be established per type of instrument, based on theassessment of the drift and its associated uncertainty, and be stated in the tender.

3.4.5 Records

All data pertaining to calibrations, adjustments (measurement data, calibration factors,events, etc.), and changes in parameters shall be registered and stored for a period of time

required by regulation or agreement. This information shall be accessible for inspection bycontract parties (witnessing).

3.4.6 Initial calibration and meter check

The initial calibration certificate of a turbine meter shall be based on a comparativecalibration against an approved and traceable metering standard. At the time of initialcalibration, a full metrology and geometry check of the meter shall be carried out. Thecalibration and checks shall together constitute the footprint of the meter, which will beused in future verifications.

3.4.7 Uncertainty

The uncertainty of the turbine meters and the secondary instrumentation shall at leastcomply with the overall metering system requirements.

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The maximum permissible planned accuracy errors shall be specified for the following:

- the components of the measuring system that can be calibrated and adjustedindividually and can be replaced in case of failure;

- the measuring system as a whole, if required by the contract. A systematic error in one

component of the measuring system shall not be cancelled out by an oppositesystematic error in another component.

3.4.8 Uncertainty analysis

The Manufacturer shall be able to demonstrate that the error of each component of themeasuring system for which a maximum permissible error has been specified and/or of the

measuring system as a whole lies within the maximum permissible uncertainty (2 ). Forthis purpose, a well-documented uncertainty analysis of the measuring system is required.

3.4.9 Station manual

The Manufacturer shall prepare a station manual comprising comprehensive and detailedinstructions for the operation, validation/calibration, adjustment, maintenance and

documentation of the primary and secondary fiscal flow measurement devices at themetering station.

These instructions shall include:

- preparation and leak testing;

- calibration of turbine meters through meter provers;

- calibration of secondary instruments: pressure, differential pressure, temperaturetransmitters, water content cell and liquid density cell;

- determination and documentation of the accuracy and measurement error per instrumentand of the overall station;

- check of signal transmission between sensors and computer;

- judgement of instrument and/or station performance, preferably via a statistical approachin order to facilitate comparison of results;

- initiating changes in calibration and maintenance intervals;

- handling and communication of acknowledged measurement deviations exceeding agreedlimits, with special attention to the notification of this sensitive information to parties andauthorities.

A practical procedure including rules for intervention in the setting of instruments andhandling of measurement deviations should be agreed between parties and include thefollowing aspects:

- Intervention shall be based on control and significance limits established per instrument or

instrument group and registered in the station manual. The control limit (CL) is themeasurement deviation that, if exceeded, justifies adjustment of the instrument. Thesignificance limit (SL) is the measurement deviation that, if repeatedly exceeded in onedirection, justifies adjustment of the instrument.

- Setting and adjustment of the limits.

- Definition of maximum allowable deviation of the total measurement system and its controllimit.

- Procedure to be followed if SL and CL are exceeded, especially as to their possibleeffects on the overall deviation of the measurement system.

- Determination of the overall deviation of the measurement system for a mutually agreedyearly averaged flow rate.

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3.5 INLET HEADER

The inlet header should incorporate the following:

- pressure transmitter and pressure gauge;

- temperature transmitter and thermowell;- temperature indicator and thermowell;

- sampling stream for the specified analyser systems (including density). Alternatively, thesampling stream may be located downstream of the meters and downstream of theprover loop connection.

3.6 METERING RUN

Parallel metering runs should be provided, each fitted with the following:

- inlet valve;

- strainer with differential pressure monitoring;

- flow straighteners;

- turbine flowmeter, complete with dual pick-ups and pre-amplifiers;

- temperature transmitter and thermowell;

- pressure transmitter and pressure gauge;

- temperature indicator and thermowell;

- stream flow control valve;

- outlet valves, one to isolate the stream and one to divert to the prover loop, with leakcheck facilities to confirm tight shut-off;

- thermal relief valves.

3.7 METER PROVER

Uni- or bi-directional mechanical displacement meter provers, generally as defined in APIManual of Petroleum Measurement Standards, Chapter 4, are currently applied. However,should the fiscal authorities accept compact proving devices, these may be applied ifapproved by the Principal.

For offshore applications, where space and weight are important considerations, either thebi-directional or compact prover will provide a smaller and lighter solution for a given metercapacity.

3.8 MICROCOMPUTER-BASED MONITORING AND CONTROL SYSTEM

Metering and meter proving shall be managed by a microcomputer system. This systemshall be installed in the CCR, LCR or local equipment room. Normally, separate

microcomputers should be dedicated to each of the metering runs, to the station and toprover control. However, the functionality of the microcomputers may be combined into oneor more computers if it can be demonstrated that the required reliability, availability andredundancy standards will be met. Such an arrangement will often be subject to approvalby local authorities.

Control of the metering station, selection of metering runs to suit production profiles, equaldistribution of flow between streams and initiation of flow meter calibration shall beexecuted from the CCR or LCR. This includes measurement and logging of pressures,temperatures, cumulative volumes, water content and density.

In view of the redundancy (to maintain production) of the metering streams, it is notconsidered necessary to provide redundancy in the individual metering stream computers.Failure of a microcomputer should be easily rectified by replacing it with a plug-in spare

unit.

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If a data link is required between the metering package and a SCADA or DCS system, theManufacturer shall liaise with the Principal and the SCADA or DCS Supplier to develop, orsupply, the necessary software system. All necessary controls, monitoring, printer anddisplay facilities shall be supplied as part of the metering system.

The input signal conditioning and analogue-to-digital conversion, including linearity,resolution and repeatability, of the microcomputer system shall be specified to have anoverall uncertainty of less than 0.020 %. The metering station measurement uncertaintydue to computation and digital output of calculated quantities shall be less than 0.001 %.

A digital transmission protocol from transmitter to microcomputer system (such as Hart orFoundation Fieldbus) is preferred to eliminate digital-to-analogue and analogue-to-digitalconversion errors.

The equipment shall be installed in a location and protected so as to minimize the effects ofelectromagnetic interference. Unless otherwise specified in the Requisition, the equipmentshall be installed in accordance with PTS 33.64.10.33

Any undesired effects that may disturb the equipment shall be taken into account, such as:

- frequent use of mobile radios and cell phones;- nearby overhead lines and substations;

- nearby welding and power switching;

- likelihood of nearby lightning strikes;

- use of long cables, possibly in parallel with power cables.

The system shall be powered by an uninterruptible electrical power supply and be able toretain for at least 31 days volatile memory data and the integrated flow totals in the event ofa power supply failure.

The signal connections between the metering skids and the microcomputer system aresummarised in (Appendix 2). The display, transfer and utilisation of data and calculatedvalues are shown in (Appendix 3).

The following features shall be included in the metering system to minimise the probabilityof undetected corruption:

- analogue signals shall have alarm settings just above and below the nominal zero andfull-scale values;

- manually entered data and configuration changes shall be protected by a key lock orother suitable security measure, e.g., password;

- any alarm, log-on, software or parameter change shall be logged with date and name ofthe initiator in an "Event Log" to provide a complete audit trail.

3.9 UTILITIES

The electrical power supply requirements shall be in accordance with PTS 33.64.10.10

The metering system will be classified as a vital service load, and complete duplication ofthe energy source and the lines of supply will be provided by Principal.

On 50 Hz systems the nominal LV power supply voltage shall be 400/240 VAC three phaseand neutral.

A.C. UPS systems shall have their neutrals solidly earthed. This applies equally to singlephase and three phase systems. The battery autonomy time for the UPS will be no lessthan 30 min after which the metering system shall provide its own back-up for retention ofall historical data and parameters.

A separate, non-vital 400/240 VAC feed for utilities will be made available for the meteringstation.

In his technical proposal, the Manufacturer shall list the expected loading of UPS.

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The Principal will provide instrument air. It shall be clean, dry and oil-free. Unless otherwisespecified, the connections on air supply lines forming part of mechanical engineering shallterminate in a inch NPT female thread. Instrument air pressure shall be as defined in theRequisition.

Only AISI 316L stainless steel tubing components shall be used on the metering skid. Forsour service (hydrogen sulfide), Monel or Hastelloy C may be used. The use of coppertubing is not allowed.

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4. TECHNICAL REQUIREMENTS FIELD-MOUNTED COMPONENTS

4.1 SKID, STRUCTURAL AND BASEPLATE

The configuration of the metering skid shall meet the requirements and comply with the

dimensional constraints of the Requisition. The Manufacturer shall propose a design withinthese constraints that combines compactness with compliance with quoted standards andcodes, and ensures maintainability of equipment.

On offshore platforms, the weight of equipment is of paramount importance and equipmentshall be designed to weigh as little as possible without degrading safety, environmentalperformance or efficiency. The Manufacturer shall identify equipment mass, centre ofgravity in relation to plan, and elevation for all assembled skid units.

The metering skid shall be of all-welded steel construction with a rigid base. The baseplateshall be adequately supported. Lifting facilities shall be provided as part of the skid andthese shall permit the complete assembly to be lifted without causing permanentdeformation or damage to the skid or to any of the equipment mounted on the skid.

Structural integrity of the skid shall not be reliant on any equipment fixed to it.

A drip-pan shall be provided over the entire skid base, inclined so that it drains to a singlepoint, which shall be designated as a hazardous drain. The drain shall be terminated in a2 in. rated ASME B16.3 150 lb. flange for connection and continuation by the Principal.Vents and drains shall be provided at all high and low points in the piping system, with thelow point drains manifolded to the baseplate edge. Visual indication shall be provided ateach drain so that liquid discharge can be observed.

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4.2 MATERIALS

Piping and Valves: all materials shall comply with the piping classes specified in theRequisition.

All other components exposed to process conditions (meters, strainers, instrumentationetc.): all materials shall comply with the Requisition; if not specifically stated on theRequisition, materials shall be selected in accordance with PTS 39.01.10.11 If anymaterials substitutions are required, these shall be approved by the Principal.

Amended perCircular 63/03

Piping design shall comply with PTS 31.38.01.10 and PTS 31.38.01.11 For EPapplications, the design shall also comply with EP 95-0230 (in particular, the minimummandatory isolation requirements).

Process inlet and outlet piping connections shall be located in accordance with theschematic drawings included with the Requisition.

The metering skid shall have a common inlet header and a common outlet header toensure uniform measuring conditions at all meter streams.

Thermal expansion relief valves are required in liquid-full systems if the system can beblocked in and subjected to heat input from atmophere or process. For the application ofthermal expansion relief valves, see PTS 80.45.10.10

Spool pieces shall be provided to replace the turbine meters during hydrotesting,installation and pre-commissioning. The spools shall be manufactured to the same pipingstandard as the skid piping and be provided complete with gaskets.

The inlet and outlet piping of parallel metering devices with common inlet and outletheaders shall have sufficient flexibility to cope with differences in thermal expansion whenone device is not in operation and to facilitate component removal.

The meter run outlet and the prover inlet and outlet valves shall be in accordance with theAPI Manual of Petroleum Measurement Standards, Chapter 4.

The meter run inlet and outlet and the prover inlet and outlet valves shall be fitted with openand closed position switches for remote indication, and a valve leakage detection alarm.The meter run inlet and outlet and the prover inlet and outlet valves shall be fitted withmanual, electric or pneumatic actuators.

Electric actuators (if fitted) shall be furnished with interposing relays to the control circuit ofthe three-phase motor. Actuator motors shall be of the cage induction type with integralstarters incorporating stall protection, limit switches and anti-condensation heaters.

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4.3 INSTRUMENTATION AND ELECTRICAL

4.3.1 Area Classification

All field-mounted electrical/electronic instruments installed in hazardous areas shall becertified for use in such locations. Refer to the Requisition Sheet for Zonal Classification,Gas Group and Temperature Class. The types of protection for electrical equipmentinstalled in hazardous areas shall be selected and implemented as defined in PTS33.64.10.10, Appendix 1. The preferred method of protection shall be as specified in theRequisition. The Principal shall approve any deviation from the preferred method ofprotection.

Equipment certification by CENELEC recognised test houses shall be obtained.

4.3.2 Climatic Conditions

Field-mounted instruments shall be suitable for operation in the prevailing climaticconditions and shall be adequately protected according to the electrical area classification.

For a description of the climatic conditions as categorized in IEC 60654-1 andIEC 60721-3-4 refer to the Requisition.

The default climatic location class in the requisition sheet is described as Class D, Outdoorlocation.

Severities of environmental parameters:

4K4is described by:

a) Low air temperature -65 C

b) High air temperature +55 C

c) Low relative humidity 4 %

d) High relative humidity 100 %

e) Low absolute humidity 0.003 g/m3

f) High absolute humidity 36 g/m3

g) Rain intensity 15 mm/min

All environments are covered by:

h) Rate of change of temp. 0.5 C/min

i) Low air pressure 70 kPa

j) High air pressure 106 kPa

k) Solar radiation 1120 W/m2

n) Condensation Yes

o) Precipitation Yes

r) Ice and frost formation Yes

4K4 applies to locations that are not protected against the weather and are directlyexposed to:

- the Restricted Group of Open-air Climates (see IEC 60721-2-1);

Warm Temperate Type of Climate

- the Moderate Group of Open-air Climates including:

Cold Temperate

Warm Dry and

Mild Warm Dry Types of Climate.

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- the General Group of Open-air Climates including:

Cold,

Warm Damp and

Warm Damp, Equable Types of Climate.

- the Worldwide Group of Open-air Climates including:

Extremely Cold and

Extremely Warm Dry Types of Climate.

plus:

4Z4 air speed up to 30 m/s

4B1 presence of mould, fungus and rodents

4C4 effects of salts and other chemicals, including hydrogen sulfide, also forcoastal areas

4S2 effects of sand and dust (this is the heaviest classification under this

category)

4M4 mechanical conditions (vibration and shock).

All electrical equipment shall be weatherproof and corrosion resistant to IP or NEMArequirements, as defined by the Principal. Junction boxes, cable racking and tray work shallbe AISI 316L stainless steel.

4.3.3 Cabling and Earthing

The Manufacturer shall provide and install all electrical cabling to connect the variouscomponents within both the metering skid and the computing facilities. Interconnectingcables between the two shall be specified by the Manufacturer for supply by the Principal.

Earthing of the system shall be the Manufacturer's responsibility and electrical equipment

shall be bonded together to form a continuous low-impedance path to earth. Each skid shallbe provided with two diagonally opposite earth bosses in accordance with StandardDrawing S 68.004. Special electronic/computer earthing requirements shall be as specifiedin PTS 32.37.20.10

Signals from the skid shall be segregated according to the various voltage levels and types.The segregation shall be in accordance with PTS 32.37.20.10

Field equipment and cabling in areas that are not protected by either earthed steelstructures or dedicated lightning conductors shall be provided with lightning protection asdetailed in PTS 32.37.20.10

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4.4 TURBINE METERS

Turbine meters shall be selected to conform to the following requirements:

Linearity of each meter shall be better than 0.25 % over a 10:1 flow range at the specified

operating viscosity. The meters shall be calibrated initially, preferably on a liquid with theviscosity for which the system is designed, or if unavailable, on water by an independentauthority. Viscosity performance shall be established when the meters are in operation. The

repeatability under stable conditions shall be better than 0.05 % of the mean pulse count.This shall be checked at minimum and maximum flow and at evenly distributed flow rateswithin the specified 10:1 range, on both water and fluid of the relevant viscosity. The formerchecks shall be carried out at the Manufacturer's works during system test and the latterduring location tests.

The turbine meters shall be provided with meter tubes and flow straighteners as necessary,in accordance with ISO 2715. Minimum upstream and downstream run lengths shall be10D and 5D respectively, where D is the inside diameter of the run.

The turbine meter installation shall ensure that the meter run remains completely filled withliquid, including during no-flow conditions.

Two pick-up heads shall be provided for the checking of pulse integrity. The design shallpermit the pick-up coils to be changed without the turbine meter being removed from themeter run. The connections shall permit sealing to the satisfaction of the appropriateauthority.

Turbine meters shall be provided with vane failure detection.

The meter calibration factor (K-factor) for each turbine meter shall be determined initially bytests carried out by the Manufacturer and entered manually or downloaded from thedatabase into each respective meter stream microcomputer.

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4.5 STRAINERS

The strainers shall be provided with the following:

- single basket stainless steel material with a mesh insert size as recommended by the

turbine meter Manufacturer;

- flanged davit closure for easy removal and replacement of basket;

- flanged vent and drain connections;

- differential pressure monitoring.

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4.6 FLOW STRAIGHTENERS

Flow straighteners shall be designed and fabricated in accordance with ISO 2715.

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4.7 FLOW CONTROL VALVES

The metering stream flow control valves should be pneumatically operated valves to controlthe proving flow from minimum to maximum conditions and to avoid hydraulic shock during

start-up and shutdowns. A side-mounted, de-clutchable handwheel should be provided formanual operation. The preferred installation of flow control valves is downstream of themeter.

The equipment Manufacturer shall perform the sizing calculations in accordance withIEC 60534-2.

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4.8 TEMPERATURE MEASUREMENT

For temperature measurement, electrical resistance thermometry shall be used. The

measurement transducer shall be a Pt 100 Platinum RTD, 100 at 0 C, alpha coefficient

0.00385

/

/C as defined in IEC 60751. Tolerance class A shall be applied.Resistance thermometers shall be interrogated directly by the relevant microcomputersutilising the four-wire technique. This is for ease of calibration and to avoid largetemperature cycles in a field mounted transmitter. Typically the temperature span will be0 C to 100 C; however, narrower spans shall be applied where operating temperaturestability permits.

The RTDs shall be mounted in flanged thermowells (refer to Standard Drawing S 38.113) toenable replacement without de-pressuring or draining the system. A test thermowell shallbe installed adjacent to the RTDs to allow a temperature check during commissioning andat periodic meter station inspections. The two thermowells shall be installed on differentradial axes to minimise vibration fatigue of the downstream well by vortex shedding from itsupstream partner.

The temperature element shall be installed and connected so that it can be readilydisconnected and extracted whenever it has to be calibrated.

Thermowells shall be provided for all temperature applications, in accordance with theapplicable piping classes. Test thermowells shall be provided with bore of minimum6.5 mm, suitable for the insertion of mercury-in-glass high accuracy thermometers. If sospecified in the Requisition, the Manufacturer shall provide two mercury-in-glass precisionthermometers for calibration check purposes. Thermometers shall be certified withaccuracy better than 0.1 C.

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4.9 PRESSURE MEASUREMENT

Pressure and differential pressure transmitters should be of the "Smart" type with ananalogue 4-20 mA output signal. They shall be in accordance with PTS 32.31.00.32

Tolerance class A shall be applied.Digital signal transmission based on generally standardised communication protocols shallbe used.

If so specified in the Requisition, the Manufacturer shall provide a precision dead-weighttester for calibration check purposes. The dead-weight tester shall be certified with anuncertainty better than half that of the pressure instruments calibrated.

To facilitate calibration, a dedicated impulse line connection to the transmitter manifoldblock shall be available to allow calibration of the transmitter from a dead-weight testerwithout the transmitter being removed from the field. Local pressure gauges shall be of theBourdon tube type with a 100 mm minimum diameter, in accordance with PTS 32.31.00.32

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4.10 DENSITY MEASUREMENT

The Manufacturer shall provide a dual parallel densitometer system. The signals of both

transducers shall be compared to monitor transducer operation. A deviation of 0.5 kg/m3to

1.0 kg/m3

(this value shall be specified by the Principal) between the two measurementsshall initiate an alarm.

A representative slipstream shall be taken from and returned to the metering station headerthrough the two vibrating-tube-type density transducers.

The physical installation and calibration verification requirements shall be as detailed in IPPetroleum Measurement Manual, Part VII, Section 2.

If so specified in the Requisition, the Manufacturer shall provide a precision densitometerfor calibration check purposes. The densitometer shall be certified with an uncertaintybetter than half that of the densitometer calibrated.

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4.11 WATERCUT MEASUREMENT

Two watercut systems are normally specified in the Requisition. The systems shall beoperated on a duty/standby basis, with the station microcomputer initiating changeover onreceipt of a system fault output. If this measurement is not used for net oil computations,

but as an operating guide only, then one watercut meter will suffice.

Sensor range shall be 0 % - 5 % water in oil with an accuracy of 0.2 % absolute.

If so specified in the Requisition, the Manufacturer shall provide a precision watercutanalyser for calibration check purposes. The watercut analyser shall be certified with anuncertainty better than half that of the watercut meter.

Correction of crude oil quantity to allow for water content shall normally be a retroactiveaccounting procedure using the results of the sample analysis(4.12).

The output of each water-in-oil measurement instrument shall be a 4-20 mA analoguesignal.

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4.13 METER PROVER

4.13.1 General

The meter prover shall be equipped with a quick-opening closure for sphere removal.The number of meter pulses generated over the calibrated volume shall be not less than10,000 pulses and resolution of the detector and sphere system shall be compatible withthis requirement. The sphere velocity shall not exceed 3 m/s. The length between detectorswitches (or round trip length for bi-directional provers) shall be at least 10,000 times thedetector repeatability. The prover connection shall be downstream of the turbine meters.

The prover shall have two dual detector switches at each end of the calibrated volume inorder to prevent the loss of the prover function in case of a faulty detector switch. Thedetector should be designed so that the contacting head of the detector protrudes into theprover pipe to ensure switching takes place at all flow rates during calibration and normaloperation. Detectors and switches shall be suitably weatherproofed for their environment.

If mechanical switches are used, each sphere detector shall have a dedicated micro-switch.

The actuation of each detector shall be set during manufacture so that, should it benecessary to replace a detector during service, there will be a negligible change in provercalibrated volume so that the accuracy of the prover will not be affected.

Connections shall be provided on the prover loop to facilitate recalibration with a portablemaster prover equipped with a master meter.

4.13.2 Four-way valve

The four-way flow diverter valve in a bi-directional prover shall be in accordance with theAPI Manual of Petroleum Measurement Standards, Chapter 4.

4.13.3 Freedom from shock

When the prover is operating at its maximum design flow rate, the sphere shall come to restsafely at the end of its travel, without shock.

4.13.4 Prover internal coating

The internal coating of the prover shall have a uniform bore and a durable and smoothsurface. The Vendor shall provide full details of the coating, maximum allowable fluidtemperature and methods of surface preparation, application, and repair. The lining shall benon-porous and not prone to explosive decompression.

4.13.5 Guide bars/tees

Guide bars or tees should be carefully designed to avoid damage to spheres.

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4.14 PAINTING

For the specification of the painting, refer to PTS 30.48.00.31-P. The painting schedule shallbe as specified in the Requisition. Colour schemes shall be as specified in the Requisition

and may be governed by local regulations and customs.

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5. TECHNICAL REQUIREMENTS - MONITORING AND CONTROL SYSTEM

5.1 STREAM MICROCOMPUTER

Each stream microcomputer shall have, as a minimum, the following facilities:

- alphanumeric displays providing interface to the operator;

- alarm/indicators for status information;

- keyboard for data entry commands, etc.

NOTE: The stream microcomputers shall have no functions other than those associated with the metering.

Each stream microcomputer shall, as a minimum, perform the following functions andwhere necessary, display relevant data:

- receive dual pulse inputs from the associated turbine meter and carry out pulse securitychecking in accordance with IP Petroleum Measurement Manual, Part XIII, Section 1;

- introduce the meter calibration factor in pulses per volume unit (often referred to as themeter K-factor), entered either manually or downloaded from the data base;

- calculate gross volume through the meter;- receive input signals from the associated pressure, temperature and density

transmitters;

- calculate the stream mass flow, utilising gross volume flow and density;

- compensate gross stream volume for the effect of pressure and temperature, to obtainnet stream reporting volumes at 15 C and 101.325 kPaabsolute;

- transmit, via the data bus, on demand from the station microcomputer, selectedmeasured and calculated variables;

- display all measured and calculated variables. The resolution on the visual display shallbe sufficient to verify the requirements for calculation accuracy;

- output alarm messages to the station microcomputer for logging and control;

- permanently display the totalised mass quantity with sufficient digits to accumulate threemonths' maximum flow without roll-over; the figures shall be stored for the time perioddeemed necessary by fiscal authorities;

- displayed manually entered parameters shall not be rounded off nor truncated;

- display on demand the totalised daily mass flow (reset to zero daily);

- operate in a fully automatic mode with the station microcomputer;

- operate in a manual mode with the operator manually launching the sphere when thestation microcomputer is out of service;

- store in memory the applicable tables detailed in ASTM D 1250-80 (or the appropriateformula and procedures), for use in compensating gross volume during normalthroughput flow;

- automatically generate an alarm and stop flow counting when flow is detected but themeter stream is not selected, i.e., off-line;

- downloading of meter calibration factors should be time stamped and identified. Thestream microcomputer should also hold the previous meter calibration factor used;

- the microcomputer system shall provide (standardised) facilities for data communicationof real time process data and totalised values with other (computer) systems.

5.2 STATION MICROCOMPUTER

The station microcomputer shall act as the prime interface for metering, entry and display ofdata. The station microcomputer shall have as a minimum the following facilities:

- alphanumeric display of all data, control requests, alarm, etc.;

- keyboard for data entry commands, etc.;

- alarm indication facility.

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The station microcomputer shall, as a minimum, perform the following functions and wherenecessary, display the relevant data:

- form a database of selected alarms, measured and calculated variables, obtained viathe data bus from the stream measurement microcomputers, or directly from the stationcommon signals;

- compile station data in an agreed format and feed this to a dedicated printer, either atspecified times or on demand from the operator;

- receive and act on keyboard commands from the operator;

- if required by the specification, interface with the SCADA or DCS system via a (serial)data link using a protocol agreed between the Manufacturer and the SCADA or DCSsystem Supplier for the two-way interchange of data;

- display valve status and selected parameters;

- display an index of all the commands and functions available to the operator;

- permanently display meter station mass flow with sufficient digits to accumulate three

months' maximum design flow without roll-over; the figures shall be stored for the timeperiod deemed necessary by fiscal authorities;

- display on demand the station daily totalised mass flow (reset to zero daily);

- proportional flow control of the sampler;

- watercut system switch over on receipt of a watercut system fault output;

- receive input signals from watercut systems for net oil calculation;

- print daily or hourly reports;

- print alarm reports.

NOTE: All functions shall be interactive and the system shall have the capacity for utilising a question-and-answer type of dialogue through the keyboard and the alphanumeric display.

5.3 PROVER MICROCOMPUTER

The prover microcomputer shall perform the following functions:

- receive a 'prove initiate' command, which may be automatic, semi-automatic, manual ora combination of these;

- check that the rates of change of prover temperature and pressure are within presetlimits;

- count raw unscaled meter pulses between detector switch operations for one proverstroke;

- correct the prover volume to operating conditions of temperature and pressure;

- calculate the meter calibration factor (the K-factor) in pulses per volume unit, inaccordance with API Manual of Petroleum Measurement Standards, Chapter 4;

- automatically conduct a series of proving runs, terminating when five consecutive runsprovide results which have a spread of less than 0.05 %;

- queue future proof runs at the operator's discretion;

- transfer data to the station microcomputer via a (serial) data link;

- control the meter run flow control valve and monitor the prover isolation valves andposition switches;

- check that the alignment of all stream prover inlets and outlets is correct;

- display four-way valve leakage alarm;

- generate and print validation (meter proving) report;

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- compare new meter factor (the K-factor) with the previous one and prompt alarm if

meter factor deviates more than 0.15 %.

The prover microcomputer shall be similar to the units described in (5.1). The provermicrocomputer shall be responsible for computing the meter calibration factor using

average temperature and pressure. This computation shall be achieved by counting rawmeter pulses from the individual stream microcomputer between detector switchoperations. The microcomputer shall provide all necessary prover sequence control.

The proving function shall be controlled from the station microcomputer via the provermicrocomputer. The 'prove initiate' command shall be transmitted to the skid equipmentwhen the following parameters are stabilised and accepted:

- prover inlet and outlet temperature;

- prover pressure;

- prover inlet and meter run outlet isolation valve seal status;

- proving flow rate.

The selection of a meter for proving shall set up an automatic sequence of valve controlprocedures. Valve seal integrity shall be monitored throughout.

If the first 5 consecutive meter-proving runs are not within the required accuracy, an alarmshould be activated to alert the operator. Should the meter fail to achieve the requiredperformance after 10 consecutive meter-proving runs, the proving sequence shall beaborted. The system should then wait for an operator command to resume the next provingrun in the queue. All calculations and reports shall be generated in the usual way foraborted runs, but they shall be annotated to indicate a failed prover run.

Should any of the prover monitored parameters exceed pre-determined limits, then theproving run shall be automatically aborted, an alarm generated and the calculationdiscarded.

On completion of a proving sequence, the revised meter factor shall be displayed. Providedthat it is satisfactory, the new meter calibration factor shall then be downloaded to therelevant line microcomputer, automatically, initiated by a command from the operator. Itshall be possible to perform this function manually if required. Should preset limits of themeter calibration factor be exceeded, then an alarm shall be initiated.

The prover microcomputer shall be provided with a re-settable high-speed totaliser, with a

minimum of eight digits, for the accumulation of meter pulses. Resolution shall be 1 pulse.

The following inputs shall be provided:

- position detector switch signals;

- inlet and outlet temperature;

- prover pressure;

- prover four-way diverter valve position status;

- valve seal status on prover inlet and meter run outlet isolation valves;

- (serial) data link from stream and station microcomputers;

- unscaled meter pulses from each individual stream meter via the stream microcomputer.

The following outputs shall be provided:

- serial data link to station and stream microcomputer;

- stream control valve;

- inlet temperature;

- outlet temperature;

- prover pressure.

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5.4 DATA INTEGRITY AND SECURITY

The overall logical and physical security of a microcomputer configuration shall bedemonstrated and ensured.

Continuously running diagnostics shall monitor the microcomputers for proper functioning

and alarm for abnormal situations. The diagnostics shall enable the station microcomputerto identify a malfunctioning stream microcomputer or data link and to initiate the appropriateaction, e.g., shut down a stream if the microcomputer is faulty, or alarm if the data link isfaulty.

The fiscal flow application shall include a security module that restricts the accessing ofparameters, the fiscal flow application itself, and maintenance and calibration functionalityto authorised personnel, and registers and stores all such accessing operations.

Each (new) version of the fiscal flow application shall be uniquely distinguished by itsversion number, displayed on both the microcomputer display and printout. The installationof new releases shall be traceable by registration of the initiator, the date, and forparameters, the as-found and as-left values.

Malfunctioning of datalink(s) between mutual microcomputers of the system and/orDCS/SCADA shall not disrupt the proper operation of the individual microcomputers.

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6. FACTORY AND FIELD INSPECTION AND TESTING

6.1 GENERAL

In addition to the provisions for testing and inspection stated in the terms and conditions of

purchase, the Manufacturer shall give the Principal adequate notice of his intention toperform tests so that arrangements can be made to witness the event.

The appropriate authority may wish to approve the equipment design and witnesscalibration tests. This requirement will be stated in the Requisition.

In the purchase order the Principal shall indicate whether or not he wishes to performinspection during fabrication. If so, the Principal shall indicate the scope of his inspection,which typically may include:

- ensuring dimensional compliance with the flow metering design;

- ensuring that the performance of instrumentation meets specification accuracy;

- ensuring that the computing system fulfils the functional performance requirements,including immunity from external interference sources;

- ensuring that the basic skid and piping fabrication meets structural and piping coderequirements;

- ensuring that the electrical/electronic installation complies with electrical safetyrequirements and that components to be used in hazardous areas have recognisedcertification.

6.2 INSPECTION FOR COMPLIANCE WITH METERING DESIGN

Metering tubes shall be inspected before they are incorporated into the pipework fabricationto ensure compliance with the requirements of ISO 2715, in particular the dimensions of theupstream flow conditioning section and of the downstream section, including the locationsof the thermowells and pressure tappings.

The turbine meter Manufacturer shall provide a calibration certificate for each meter. Thecalibration shall be carried out by an accredited laboratory (in accordance with ISO 9002)and be traceable to national standards. If possible, the calibration fluid should have asimilar viscosity to the specified operating liquid. If this cannot be achieved, calibrationusing water shall be performed, with account being taken of the Manufacturer's predictionof performance on the operating liquid.

An independent accredited calibration company shall calibrate the meter prover at theManufacturers premises. The calibration should be witnessed by the appropriate authorityand recorded on a formal certificate.

The instruments detailed in (4.4,4.7,4.8,4.9,4.10and 4.11)shall be inspected and testedin accordance with PTS 62.10.08.11

6.3 INSPECTION AND TESTING OF PIPING SYSTEMS

All materials used in fabricating the process pressure-retaining system, e.g., pipework,valves, fittings, etc., shall have relevant mill certificates, casting melt certificates, etc., inaccordance with the applicable MESC specification.

Prior to commencement of fabrication, the welder(s) for the process piping fabrication shallbe certified to the requirement of the piping design specification.

During fabrication, welds shall be inspected as defined in PTS 31.38.01.31 Records shallbe kept and witnessed as appropriate.

Hydrostatic pressure tests shall be performed in accordance with ASME B31.3 and PTS31.38.01.31 Specifically, the entire pipework system shall be maintained at maximum ratedpressure for the recommended time, following removal of the turbine meters and their

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replacement by pipe spools. A certified chart record of temperature and pressure shall beproduced covering the duration of the test.

All flanges and swing elbows shall be capable of being opened without pipe spring ormalfunction. The Principal may require the Manufacturer to open joints for spot checks.

6.4 INSPECTION FOR ELECTRICAL SAFETY

Safety documentation for the selected type of protection for the installed electricalinstruments shall be compiled for scrutiny and to ensure that any certification requirementshave been incorporated in the installation.

All wiring shall be tested for insulation resistance, earth fault and earth continuity. Toprevent damage to low-voltage equipment, the instrument equipment shall be disconnectedat both ends of the cable before these tests are carried out and re-connected prior to thefunctional tests.

All terminations, glands, junction boxes and other electrical and electronic equipmentenclosures on the skid shall be inspected for correct application, assembly and closure.

6.5 CALIBRATION FACILITIES

The following calibrating facilities shall be included, if so specified in the Requisition:

- temperature bath for temperature elements (after removal from the thermowell);

- dead-weight tester for pressure transmitters (transmitters to remain in the field, onlymanifold valves to be switched using dedicated impulse lines to the console);

- calibration liquid for the densitometer (facilities shall be provided to allow the calibratingfluid to be routed through the densitometer at the required rate);

- calibration liquid for the watercut meter (facilities shall be provided to allow thecalibrating fluid to be routed through the watercut meter at the required rate);

- Hart communicator;

- portable pressure calibrator.

If a dead-weight tester is included in the calibration equipment, the Manufacturer shalldetermine the gravitational constant for the location of the metering station. This constantcan be calculated based on a formula from the International Association of Geodesy (seeaddress below) with data derived from satellite orbital variations (1970) and is always to

within 10-3m/s2and usually within 5 x 10-4m/s2.

NOTE: International Association of Geodesy Central Bureau,c/o Department of Geophysics,Juliane Maries Vej 30,DK-2100 Copenhagen ,Denmark.

6.6 MASS AND VOLUME FLOW COMPUTATION SYSTEM

6.6.1 Functional tests

A detailed test programme to confirm compliance with the design requirement shall bedeveloped by the Manufacturer for approval by the Principal. These tests shall include, butnot be limited to the following:

- functional and performance check of all conversions of analogue and frequencymeasured variables into digital values;

- confirmation of correct flowrate computation and quantity integration operations withsimulated measurement inputs;

- confirmation of correct output signals to the totalisers, analogue indicators or recorders,meter prover, watercut measurement, sampler and SCADA or DCS systems;

- confirmation of correct generation of operating function alarms, e.g. high flow rate, etc.;

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- confirmation of computer system and health monitoring alarms;

- confirmation of event logging and reports;

- demonstration of immunity of the system to electromagnetic interference in accordancewith (3.8);

- demonstration of short circuit protection of inputs and outputs. A representative sampleof inputs and outputs shall be subjected to sustained short circuit, to ensure that devicescan survive both a fleeting and a sustained short circuit;

- demonstration that malfunction of an input/output channel shall not cause failure of anyother input/output channel;

- demonstration that signal isolation between input or output channels shall be clearlydefined;

- demonstration of auto start-up and recovery after power failure;

- functional check of a representative sample of spare parts by inserting these into themain equipment and performing tests described above;

- functional check of Manufacturer/Supplier-supplied tools and test equipment with themain equipment.

NOTE: The tests are to be made over the full ambient temperature range to demonstrate statisticalcompliance with design criteria.

6.6.2 Heat-soak tests

The system shall be operated by the Manufacturer in its final on-site configuration for aminimum period of 200 h (burn-in period). A minimum of 10 % of digital inputs, 10 % ofdigital outputs and all analogue inputs and outputs shall be simulated for this period, withsimulation equipment provided by the Manufacturer.

All deliverable equipment used in the system shall be subjected to an elevated temperatureof 45 C (typical) for 100 h during the demonstration period. The system environment shallbe cycled between 45 C and the site ambient temperature at 12-h intervals, until the 100-helevated temperature period is completed.

During the heat-soak test, the system equipment shall be fully energised. Fully-loadedoperating conditions shall be simulated at 24-h intervals by demanding reports, selectingdisplays, exercising calculations and sending and requesting data over communicationchannels.

If a component failure occurs, all tests shall be repeated after the replacement of the faultycomponent, unless otherwise agreed by the Principal. This ensures that all essentialcomponents are subjected to the specified minimum testing.

6.6.3 Dynamic tests

A specific programme of dynamic tests shall be agreed between the Manufacturer and thePrincipal. The programme shall include but not be limited to the following tests:

- verification that meter run and meter prover selection valves operate correctly, that thevalves seal, and correctly signal the valve positions;

- verification that the meter stream flow control valves function correctly and that flowbalance between meter runs is achieved;

- verification that the measurement data presented at the operator's interface to themicrocomputer are correct and that commands given at the interface are executedcorrectly;

- verification that alarms are initiated at appropriate measurement conditions;

- demonstration of all event, alarm, and routine log formats.

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6.7 FUNCTIONAL TESTING OF THE COMPLETE METERING SYSTEM

The wet functional test shall demonstrate that all the sub-systems, already tested inisolation, operate successfully as an integrated system under actual flowing liquidconditions.

The Manufacturer shall assemble the complete metering system, or sub-system such as asingle stream, for a functional test. The assembly shall include a suitable pump or pumps, aliquid break tank and additional temporary pipework to allow inhibited water to be circulatedthrough the system. The pump(s) and temporary facilities shall be capable of achieving avariable flow rate up to at least twice the capacity of a single meter run. All measurementtransducers shall be installed and connected by temporary cables to the microcomputersand all control output signals from the microcomputers to selection valves, control valves,etc., shall be connected and commissioned.

All aspects of system software, including any required data link protocol, shall be testedduring the system functional test to ensure correct operation. This testing shall includeconnecting the system to a device that simulates the full control system (DCS/SCADA, etc.)to ensure correct reflection of metering data. Such a device may need to be provided by the

DCS/SCADA supplier.After satisfactory completion of the functional tests, the test liquid shall be drained off andthe piping system dried, e.g. by blowing through warm dry compressed air.

It should be noted that the water quality to be used for functional testing depends on thematerial(s) from which the equipment is manufactured.

The special water and drying requirements to be met are the same as for "HydrostaticPressure Test" as specified in PTS 31.38.01.31

6.8 WATERCUT MEASUREMENT, DENSITY MEASUREMENT AND SAMPLERS

Sections(6.1,6.3and 6.4)also apply to these systems.

These systems should be tested as part of the functional test described in(6.6).If this is notpossible, the Manufacturer shall develop a site acceptance test. This shall include afunctional test of each system, including any interface with the main metering skid and itsmicrocomputers.

6.9 SITE ACCEPTANCE TEST

The site acceptance test shall be developed by the Manufacturer to demonstrate that thecompletely assembled and installed metering system, including meter-prover, watercutmeasurement, density measurement and samplers at the metering station, operatessuccessfully under real conditions on the real process fluid, and communicates properlywith the live DCS/SCADA system.

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7. PRESERVATION AND PREPARATION FOR SHIPMENT

7.1 PRESERVATION

Full consideration should be given to the need for long-term preservation of the skid and

metering electronics after testing has been completed. The Manufacturer shall furnishrecommendations for long-term preservation (18 months) at a designated site for theperiods prior to installation and after float-out for an offshore installation.

7.2 PREPARATION FOR SHIPMENT

All packaging shall be in accordance with BS 1133.

The Manufacturer shall provide a complete packaging and handling specification to coverboth skid and electronic panels.

Prior to shipment, all high-accuracy skid-mounted instruments and densitometers shall beremoved, packed separately, and shipped with the skid. Turbine meters shall be replacedwith pipe spools and shipped with the skid.

The skid pipework shall be prepared and sealed for preservation purposes. TheManufacturer shall provide blanking flanges as well as filling and draining facilities.

Painting of the complete assembly shall be suitable for the location and in accordance withPTS 30.48.00.31-P.

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8. DOCUMENTATION

8.1 REQUIREMENTS

The Manufacturer shall supply the documentation in accordance with the Data Requirement

Schedule of the Requisition.In addition to the foregoing, the Manufacturer shall provide the following information:

8.2 MANUALS

During the manufacture, testing, installation and final commissioning, a system dossiershall be assembled containing as a minimum:

- a narrative description of the metering function, design philosophy, and operatingprocedures and conditions;

- methods and criteria for measurement corrections in case of dispute;

- process engineering flow schemes of the metering system, showing breakpointsbetween upstream and downstream process equipment;

- design specifications and Manufacturer documentation for the component parts of thesystem;

- a computer handbook documenting the equations and routines being used;

- calculations for flow metering system uncertainties utilising as-built dimensions andperformance criteria;

- agreed tolerances of measurement;

- a list of alarms (diagnostic as well as operational);

- the full calibration audit trail of all equipment used in calibration;

- witnessed results of computing system inspection and testing;

- outline of prover calibration and verification methods;

- listing of computer programs;- material certificates of all piping and equipment items;

- operating and maintenance manuals containing, amongst other methods, proceduresand criteria applicable for the quality assurance of the flow measuring station;

- spare parts list as defined in PTS 70.10.90.11

8.3 CERTIFICATES

- electrical equipment certification for hazardous areas;

- calibration certificates and calibration references for meters and prover;

- calibration certificates for the calibration and test equipment.

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9. REFERENCES

In this PTS reference is made to the following publications:

NOTE Unless specifically designated by date, the latest edition of each publication shall be used, togetherwith any amendments/supplements/revisions thereto.

PETRONAS STANDARDS

Index to PTS publications and standardspecifications

PTS 00.00.05.05

Index to standard drawings PTS 00.00.06.06

Protective Coatings & Lining PTS 30.48.00.31-P

Piping classes - basis of design PTS 31.38.01.10

Piping - general requirements PTS 31.38.01.11

Shop and field fabrication of piping PTS 31.38.01.31

Instruments for measurement and control PTS 32.31.00.32Turbine fiscal metering system for liquidhydrocarbons

PTS 32.32.00.93

Instrument signal lines PTS 32.37.20.10

Electrical engineering guidelines PTS 33.64.10.10

Electromagnetic compatibility (EMC) requirements PTS 33.64.10.33

Selection of Materials for Life Cycle Performance(EP)

PTS 39.01.10.11

Inspection and functional testing of instruments PTS 62.10.08.11

Spare parts PTS 70.10.90.11Pressure relief, emergency depressuring, flare andvent systems

PTS 80.45.10.10

Amended perCircular 63/03

Safety engineering in facilities design EP 95-0230

Materials and Equipment Standards and Code MESC

PETRONAS STANDARD DRAWINGS

NOTE: The latest edition of Standard Drawings can be found in PTS 00.00.06.06

Flanged thermowell DN 40, ASME classes up to

1500 incl.

S 38.113

Earthing boss for steel structures, tanks, vessels,etc.

S 68.004

AMERICAN STANDARDS

Malleable iron threaded fittings classes 150 and 300 ASME B16.3

Process piping ASME B31.3

Issued by:American Society of Mechanical EngineersASME InternationalThree Park AvenueNew York NY 10016-5990USA

Manual of petroleum measurement standardsChaper 4 Proving systems

API MPMS 4.1 4.8

Issued by:
http://00000505.pdf/http://00000606.pdf/http://30480031-p.pdf/http://31380110.pdf/http://31380111.pdf/http://31380131.pdf/http://32310032.pdf/http://32372010.pdf/http://33641010.pdf/http://33641033.pdf/http://39011011.pdf/http://62100811.pdf/http://70109011.pdf/http://80451010.pdf/http://80451010.pdf/http://70109011.pdf/http://62100811.pdf/http://39011011.pdf/http://33641033.pdf/http://33641010.pdf/http://32372010.pdf/http://32310032.pdf/http://31380131.pdf/http://31380111.pdf/http://31380110.pdf/http://30480031-p.pdf/http://00000606.pdf/http://00000505.pdf/

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American Petroleum Institute1220 L StreetNorthwest Washington, DC 20005, USA

Standard guide for petroleum measurement tables ASTM D 1250

Issued by:

American Society for Testing and MaterialsASTM International100 Bar Harbor DriveWest Conshohocken, PA 19428-2959USA

BRITISH STANDARDS

Packaging code BS 1133

Issued by:British Standards Institution389 Chiswick High RoadLondon W4 4ALUK

Petroleum Measurement Manual IP Code- Density, continuous density measurement Part VII, Section 2

- Fidelity and security of measurement datatransmission systems, electric and/or electronicpulsed data cabled transmission for fluid meteringsystems

Part XIII, Section 1

Issued by:Institute of Petroleum61 New Cavendish StreetLondon W1M 8ARUK

INTERNATIONAL STANDARDS

Industrial-process control valves. Part 2: Section 1-Sizing equations for incompressible fluid flow underinstalled conditions

IEC 60534-2

Industrial-Process Measurement and Control Equipment -Operating Conditions - Part 1: Climatic Conditions

IEC 60654-1

Classification of environmental conditionsPart 2 Environmental conditions appearing in naturaltemperature and humidity first edition

IEC 60721-2-1

Classification of Environmental ConditionsPart 3: Classification of Groups of Environmental Parametersand Their Severities - Section 4: Stationary Use at Non-Weatherprotected Locations

IEC 60721-3-4

Industrial platinum resistance thermometer sensors IEC 60751

Issued by:International Electrotechnical Commission3 Rue de Varemb1211eva 20Switzerland

Copies can also be obtained from most national standardsorganisations.

Liquid hydrocarbons; Volumetric measurements byturbine meter systems

ISO 2715

Petroleum liquids Manual sampling ISO 3170

Petroleum liquids Automatic pipeline sampling ISO 3171

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Measurement of fluid flow Evaluation ofuncertainties

ISO TR 5168

Quality systems Model for quality assurance inproduction, installation and servicing.

ISO 9002

Issued by:Central Secretariat of ISO1 Rue de Varmb1211eva 20Switzerland

Copies can also be obtained from most national standards organisations.

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APPENDIX 1 TYPICAL LIQUID HYDROCARBON FISCAL MEASUREMENT FLOW SCHEME

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APPENDIX 2 FIELD SIGNAL CONNECTIONS AND TRANSFER

SIGNAL MICRO COMPUTER

DESCRIPTION Type MeterRun

MeterProver

Station

pulse train from turbine meter (dual) F XX PP

density transducer frequency (2 off) F XX XX

meter run outlet pressure A/H X T T

meter run outlet temperature () X T T

meter prover pressure A/H T X T

meter prover inlet temperature () T X T

meter prover outlet temperature () T X T

meter station inlet header pressure A/H X

Watercut A T X

density transducer inlet header pressure A X

meter station outlet header pressure A/H X

meter station outlet header temperature () X

meter run outlet valve status S X T T

meter run outlet valve leakage signal S X T T

meter run proof inlet valve status S X T T

meter run proof inlet valve leakage signal S X T T

meter prover 4 way, or launch, valve status S X

meter prover 4 way valve leakage signal S X T

meter prover detector switches (4 off) S XXXX

meter run outlet valve open/close command S X

meter run proof valve open/close command S X

meter run outlet flow control valves modulatedcontrol

A/H X

meter prover 4 way (launch) valve command S X

total flow proportional signal to sample system A X

A = AnalogH = Hart or another digital protocolF = FrequencyP = Connection only when a particular meter is in proof operationS = Change of state (digital)T = Data transferred from microcomputer having primary connectionsX = Primary connectionsNote: Temperature is not analog as it is a four-wire connected to the A/D converter in the

microcomputer.

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APPENDIX 3 DISPLAY, TRANSFER AND UTILISATION OF DATA AND CALCULATEDVALUES

DATA MICRO COMPUTER

Meter Run Meter Prover Station

turbine meter pulse counts (dual) S S

turbine meter 'k' factor D S D

gross volumetric flow-rate S D D

gross standard volumetric flow-rate S D D

density transducer periodic time (2 off) D or S S

density computed (2 off) D or S S

meter run outlet pressure S D D

meter run outlet temperature S D D

mass flow-rate per meter run S D

accumulated volume, per meter run S D

accumulated mass, per meter run S D

total volumetric flow-rate for metering station S

total mass flow-rate for metering station S

accumulated volume for metering station S

accumulated mass for metering station S

pulse discrepancy counter, per meter run S D

density transducer constants (key-pad entered) D S

high and low flow alarms, per meter run S D

density deviation alarm S

turbine meter counts per proof run (dual) S D

meter prover pressure S D

meter prover inlet temperature S D

meter prover outlet temperature S D

meter run outlet valve status (per meter run) S D

32320011 Sep 02

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